Add a Site Icon
You can upload a site icon by following these steps:
On the main menu, go to Appearance → Customize
3. Click on Site Identity.
4. Click on Select logo to update a logo and Site Icon to add an icon. Your Media Library will be shown. Choose an existing image or upload a new one.
5. Click Select. You may then be given an option to crop the image to make sure it’s square. You can also skip the cropping step if you wish.
6. Click the Save Changes button when you’re happy with the icon.